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start using PPC predicates more consistently.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31833 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
2006-11-17 22:10:59 +00:00
parent b1409ce7ba
commit df4ed6350b
10 changed files with 118 additions and 60 deletions
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28
lib/Target/PowerPC/PPCBranchSelector.cpp
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@@ -18,6 +18,7 @@
#include "PPC.h"
#include "PPCInstrBuilder.h"
#include "PPCInstrInfo.h"
#include "PPCPredicates.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetAsmInfo.h"
@@ -125,19 +126,36 @@ bool PPCBSel::runOnMachineFunction(MachineFunction &Fn) {
// 1. PPC branch opcode
// 2. Target MBB
MachineBasicBlock *DestMBB = MBBI->getOperand(2).getMachineBasicBlock();
unsigned Opcode = MBBI->getOperand(1).getImmedValue();
PPC::Predicate Pred = (PPC::Predicate)MBBI->getOperand(1).getImm();
unsigned CRReg = MBBI->getOperand(0).getReg();
int Displacement = OffsetMap[DestMBB->getNumber()] - ByteCount;
unsigned Inverted = PPCInstrInfo::invertPPCBranchOpcode(Opcode);
bool ShortBranchOk = Displacement >= -32768 && Displacement <= 32767;
// Branch on opposite condition if a short branch isn't ok.
if (!ShortBranchOk)
Pred = PPC::InvertPredicate(Pred);
unsigned Opcode;
switch (Pred) {
default: assert(0 && "Unknown cond branch predicate!");
case PPC::PRED_LT: Opcode = PPC::BLT; break;
case PPC::PRED_LE: Opcode = PPC::BLE; break;
case PPC::PRED_EQ: Opcode = PPC::BEQ; break;
case PPC::PRED_GE: Opcode = PPC::BGE; break;
case PPC::PRED_GT: Opcode = PPC::BGT; break;
case PPC::PRED_NE: Opcode = PPC::BNE; break;
case PPC::PRED_UN: Opcode = PPC::BUN; break;
case PPC::PRED_NU: Opcode = PPC::BNU; break;
}
MachineBasicBlock::iterator MBBJ;
if (Displacement >= -32768 && Displacement <= 32767) {
if (ShortBranchOk) {
MBBJ = BuildMI(*MBB, MBBI, Opcode, 2).addReg(CRReg).addMBB(DestMBB);
} else {
// Long branch, skip next branch instruction (i.e. $PC+8).
++NumExpanded;
BuildMI(*MBB, MBBI, Inverted, 2).addReg(CRReg).addImm(2);
BuildMI(*MBB, MBBI, Opcode, 2).addReg(CRReg).addImm(2);
MBBJ = BuildMI(*MBB, MBBI, PPC::B, 1).addMBB(DestMBB);
}